Reply To: coverage database for multiple simulation

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Jim Lewis

Hi Juhi,

Yes.  If you run a test case with a different seed, it will do the randomization in a different order. 

Yes, if you write out the two databases separately using WriteCovDb, they can be read in and merged use OSVVM ReadCovDb.   However, keep in mind, this is not SystemVerilog which does not in any way correlate the coverage with the randomization during run time.   Instead, OSVVM Intelligent Coverage based randomization is always intended to reach your coverage goals and stop (if you are running until CovModel.IsCovered).  Hence, when you merge the two separate databases, you will get the sum of the coverage goals – not something that is all that exciting or useful. 

The only time you may not reach your coverage goals is if you are collecting functional on outputs and generating stimulus for inputs that are intended to generate the next desired output.  If you make a mistake in your mapping from outputs to inputs, then it is possible that a given output sequence will never happen – however, changing the seed in this case is unlikely to help any at all.